Hi there,
Yep YAA is available even to uni students, and is quite popular.
Start up cost really depends on the type of business you strive for,
if your a student I'd recommend running it from home, the cost to rent space isn't worth it at this stage, since you'd be at school most of the time or at uni
Also what you can do in rented space you most likely can do from your own home unless it includes equipment and such as part of the property being rented - which then makes definitely out of reach of students
Tutoring agencies are booming, there's lots of kids out there who want to better their education, and their parents are willing to give an arm and leg for it.
If you do run a tutoring agency, please run it properly and be ethical, there are lots of dodgy tutors out there who profit heaps, the students just don't seem to want to move away or something
To start tutoring, perhaps tutor a few kids and news will spread, amongst chit-chat at parent work places etc, when you can't handle a few kids you could refer them to someone else for a small fee or something, thats' something you can work out how you'd like it run
To the dude that asked about setting up a business in nsw, check out:
http://www.business.nsw.gov.au/ - it's an awesome resource.
I'm currently studying a business elective specifically for starting my own business, Innovation and Small Venture Management in the school of management at UTS, Faculty of Business.
I'm also looking into starting my own business in 2 areas, freelance webdesign at the end of this year and one other, I'm doing all the research needed before jumping into the deep end, there's a lot to consider, one that many people fail to recognise is how they will pass on, or get out of the business once it no longer interests them, or even becomes too succesful!
I'm also doing YAA in a company called Yacht Buoy, we won the marketing award yesterday at the 2004 Trade Fair and Ive learnt so much through YAA, I very highly recommend it, if your willing to put in the hard yards
Anyway, post is getting long, hope something I've posted has been useful!